Two Particularly Evolutionary Loci of matK of cpDNA of Genera of Magnoliaceae

In order to quickly identify Magnoliaceae plants and scientifically correct the misidentification of the samples of chloroplast complete genomes in the NCBI (National Center for Biotechnology Information, USA) database, total 260 samples of Magnoliaceae, 196 of Yulania Spach, 40 of Magnolia L., 19 of Michelia L., and 5 of Liriodendron L. were collected and the partial sequences of matK gene were amplified and sequenced respectively. The results indicated that there are two particular loci in the partial sequences, matK (...AAGNAATGATTGTATAA...CCAAAAATMGACAAGGTG...) (N = A, G; M = A, G, T) of Magnoliaceae, which can be used to identify the family because they are not possessed by other families. They are also PEL (particularly evolutionary loci) of genera of Magnoliaceae, which can be used to quickly identify the genera of the family, for all samples of the genus of Yulania Spach with the loci of matK (...AAGGAATGATTGTATAA...CCAAAAATAGACAAGGTG...), all samples of Magnolia L. with matK (...AAGGAATGATTGTATAA...CCAAAAATGGACAAGGTG...), all samples of Michelia L. with matK (...AAGAAATGATTGTATAA...CCAAAAATGGACAAGGTG...), and all samples of Liriodendron L. with matK (...AAGGAATGATTGTATAA....CCAAAAATTGACAAGGTG...). So, In four genera of Magnoliaceae, Yulania Spach, Michelia L. and Liriodendron L. have the respective PEL, and Magnolia L. can also be easily identified for having the oppositely evolutionary loci of other 3 genera. Based on the two PEL, the misidentified samples of chloroplast complete genome in NCBI were listed, which included 11 samples of Yulania Spach and 3 samples of Michelia L.. Being simple and reliable, PEL is a scientific method to identify the evolutionary taxa, which can effectively overcome the limitations of being partial and subjective in Taxonomy and Phylogeny.